Blast-furnace smelting.



J. W. NBSMITH. BLAST FURNACE SMELTING. APPLICATION FILED mm: 12, 1909.

Patented Jan. 19,

n: NORRIS vEYERs co., msmunmu. n. a

UNETED STATES PATENT OFFKQE.

JOHN W. NESMITH, OF DENVER, COLORADO, ASSIGNOR TO COLORADO IRON WORKS COMPANY, OF DENVER, COLORADO.

BLAST-FURNACE SMELTING.

T all whom 2'2, may concern Be it known that I, J OHN W'. NnsMrrn, citizen of the United States, residing at Denver, Colorado, have invented certain new 5 and useful Improvements in Blast-Furnace Smelting, of which the following is a specification.

My invention herein described relates to the treatment of oxidized ores.

The invention is an improvement in the smelting method as heretofore practiced and consists in supplying heat generated outside the furnace, to the shaft thereof, preferably from crude petroleum or gas, the heat thus supplied being utilized in lieu of the solid carbonaceous fuel, as coke, charcoal or their equivalents theretofore used. The method includes supplying air to the furnace, independently of the heat generated outside and forced into the furnace.

An apparatus for carrying the invention into effect is illustrated in the accompanying drawing, in which the figure is a sectional view.

I utilize a blast furnace shaft of the same general design as those in common use for pyrite smelting or copper matting, and, with some modifications, for lead smelting, and ha ting auxiliary thereto a fire-box or combustion chamber of suitable proportions for burning the necessary quantity of crude oil or petroleum, to supply an adequate equivalent of heat to the shaft of the furnace into which the ores and fluxes for smelting are charged, to consummate the smelting continuously to completion as such ores and fluxes are charged in, the heat from the crude oil or petroleum being used instead of coke, or other solid carbon, as fuel only, in oxidizing smelting and not for producing any other reactions involved.

The oil or gas fuel in this system is burned in a fire box or combustion chamber, segregated entirely as to combustion from the ores and fluxes being smelted in the blast furnace, so that the chemical reactions incident to the combustion of carbonaceous fuel for the production of heat necessary for smelting shall not take place in contact with the ores being 50 smelted, in order to avoid the complications involved in burning carbonaceous fuel in contact with the ores and fluxes or with the air blast in a smelting operation whose necessary reactions are Wholly oxidizing, as in smelting sulfid ores to a regulus or matte product Specification of Letters Patent.

Application filed June 12, 1908.

Air is blown into such a furnace for the purpose of furnishing the oxygen necessary to oxidize the waste materials, as the sulfur and the iron of the sulfid ores, the latter to iron oxid to combine with the silica in the ore to form a fluid slag to How freely away to the dump, the sulfur up the chimney to the atmosphere.

Oxygen has a stronger affinity for carbonaceous fuel, as coke or charcoal or oil, than it has for iron or sulfur, and hence when such carbonaceous fuel'as coke or charcoal or oil is charged into the furnace with the ores, or as oil is burned in the air blast of the furnace, no reaction can take place of oxygen with iron and sulfur until the carbonaceous fuel has been fully satisfied with oxygen or unless there is a surplus of oxygen going into the furnace over and above that demanded by the carbonaceous fuel. In other words, the combustion of carbonaceous fuel in the atmosphere of the blast furnace smelting to a matte product, is essentially counteractive of the oxidizing reactions involved in such smelting methods, and hence the use of carbonaceous fuel burning in contact with ores being smelted, under the action of the air blast is entirely avoided in this method.

In my improved method the heat, necessary to be supplied to the smelting furnace, is produced by burning oil or gas to its ultimate products of combustion in a combustion chamber outside of the blast furnace where the ore is smelted, and the heat so produced is conveyed by convection through suit-able ducts together with the inert gases of combustion, into the smelting furnace, and so the necessary heat for smelting the ores is supplied to the furnace without the counteractive effect involved where carbonaceous fuel is burned in the atmosphere of the furnace or in contact with the ores being smelted.

In some cases, so much coke or other hard carbon is used in the furnace stack with the ores as is necessary to the reducing reaction from oxid to metal or other necessary reactions of such nature involved in such reducing smelting, but no hard carbon is used in the furnace stack for producing heat, or for other purposes than that named above.

In the drawings, A is a blast furnace of usual construction, having twyers B. A fire box or combustion chamber is shown at O,

in which petroleum or other fluid or gaseous hydrocarbon is burned for the production of heat.

H is a pipe leading from a blower of usual heat, with the products of combustion generated in the fire box are forced directly into the blast furnace against the pressure, if any, maintained in the blast furnace stack A by the air blast from the blower supplying the twyers.

E is a general form of bustle pipe with an air'duct F delivering the air blast from a blower necessary to the process of smelting the ores in the stack. One form of such air duct F (Fig, 2) is made as a slot or rectangular opening parallel with the plane of the furnace'hearth, and preferably of such proportions as to admit the full blast of air fromthe blower G without constriction, as is involved in theruse of the twyers B shown in Fig. 1 and commonly employed at the entrance to the furnace. Some air may be necessary in the'reducing furnace for such ofiice, among other things, as producing car'- bon monoxid from coke or charcoal charged on'with the ores for reducing oxids to metals.

The twyers B or the air blast duct F, as the case may be, and the heat duct D in the form shown, enter the furnace A preferably in so near proximity to each other that the heat and heated gases from the combustion chamber C meet and-commingle with the air blast, if any, within the blast furnace, thus warming or heating the air blast immediately 011 its entrance and avoiding the paralyzing effect of cold air in the smelting Zone, while at the same time the heat over and above that utilized for heating the air in the blast furnace A necessary for the smelting operation, is provided through the heat duct D from the combustion chamber C.

In this method of smelting to lead base bullion or other metals, it is also convenient to use liquid or gaseous fuel as a reducing agent, to which the air may be accurately supplied in such proportions as to produce carbon lnonoxid and thus secure perfect and complete reduction of oxide to their metals.

I claim The herein describedmethod of treating oxidized ores, which consist in feeding a mixture of ores and fluxes and such carbonaceous material as is necessary for the reactions involved in the reduction of such ore to metals into a blast furnace, burning a suit able fuel exterior to the blast furnace and passing the hot combusted products into the WVINTHROP R. CADY, H. B. LOWDEN. 

